1. Field of the Invention
The invention relates to a dispenser for flowable soap.
2. Description of the Prior Art
Most dispensers for flowable soap are currently manually operated, which means that the dispenser must be touched when soap is to be dispensed. Since it is unsanitary to touch the dispenser, it would be desirable to be able to obtain soap without touching the dispenser.
Accordingly, several automatic dispensers have been developed employing two distinct principles for delivering fluid from a reservoir. The first technique makes use of a pump, which can be solenoid operated, rotating-cam operated, or actuated by deformation of a flexible reservoir. Pumps are inefficient in this type of application because any change in the kinetic or potential energy of the fluid must be provided by the electrical source energizing the pump.
More efficient devices use gravity to provide the force necessary to move the liquid. Accordingly, another technique is to position an electrically actuated valve below the fluid reservoir. When the valve is opened, the fluid is forced through it by gravity. This design is necessarily inefficient because the aperture size of the valve must be adapted as a function of the viscosity of the fluid that must flow through it. Thus, larger apertures require more energy to open them. Therefore, a more efficient automatic-dispenser design would be desirable for reasons of economics and energy conservation.
It is an object of the invention to eliminate the need for touching a dispenser in order to dispense a liquid such as soap therefrom.
Another objective of the invention is a design for an automatic dispenser that is suitable for liquids of various viscosities.
Another goal is a dispenser that utilizes gravity as the motive force for the liquid being dispensed.
Still another goal is a dispenser that operates with increased efficiency regardless of the viscosity of the liquid being dispensed.
Another objective is a design that can be implemented efficiently and economically.
Still another object is a dispenser that prevents dripping of the dispensed liquid between uses.
The preceding objects, as well as others which will become apparent as the description proceeds, are achieved by the invention.
One aspect of the invention resides in a dispenser for a liquid, such as liquid soap. The dispenser comprises a container for a supply of soap, and the container is provided with at least one opening for discharging soap therefrom. The dispenser further comprises means for detecting objects at a spacing from the container, and means for controlling the passage of soap through the discharging opening. The controlling means has a first condition in which soap is free to pass through the discharging opening and a second condition in which the passage of soap through the opening is inhibited. The controlling means is designed to assume the first condition in response to the detection of an object by the detecting means and to revert to the second condition in response to discontinued detection of the object. The detecting means can detect a hand which is spaced from the dispenser and is designed so that soap is dispensed when a hand is detected. Hence, the dispenser in accordance with the invention makes it unnecessary to touch the dispenser in order to obtain soap therefrom.
According to another aspect of the invention, the dispenser consists of a closed reservoir having a dispensing opening at its lower extremity through which the liquid can flow. As the fluid flows out of the reservoir through the opening, the pressure at the top in the reservoir is gradually reduced until the pressure differential between the inner top portion of the reservoir and the ambient, external atmospheric pressure is sufficient to stop the flow of fluid. An electrically actuated valve is positioned to admit air from outside the reservoir into the upper, low pressure, area of the reservoir to allow the fluid to flow from the reservoir through the lower opening.
Another aspect of the invention resides in a method of operating a soap dispenser. The method comprises the steps of placing an object at a predetermined location spaced from the dispenser, sensing the object while the object is at such location, and dispensing soap from the dispenser in response to the sensing step. The sensing step may include detecting energy reflected from the object, and the energy can comprise infrared radiation. The method can further comprise the steps of removing the object from the predetermined location, discontinuing the sensing step upon removal of the object from this location, and terminating the dispensing step in response to discontinuation of the sensing step.
The method may also comprise the step of inhibiting the dripping of soap from the dispenser subsequent to the terminating step. The dispenser can include a soap container and a supply of soap in the container, and the dispensing step may involve establishing communication between the soap supply and the atmosphere.
Additional features and advantages of the invention will be forthcoming from the following detailed description of preferred embodiments when read in conjunction with the accompanying drawings.